Medical Mystery Monday #69: the case of the developmental reversal

A 4 year old boy is brought to the doctor by his parents because many of his developmental milestones have been reversing. They have been to multiple pediatricians, but no one has been able to diagnose their son’s condition. The patient’s problems began when he was 6 months old and was noted to have yellow skin (jaundice) and an enlarged liver and spleen, but the cause was never determined. The patient’s development was nearly normal, learning to walk and talk a little later than average. However, the patient’s parents describe that over the last year, he has seemed to go backwards in his development. He now barely speaks to them and needs to hold his parents’ hands when he walks or else he falls over. He has started to sleep more than usual, and has had difficulty swallowing his food.

On physical examination, the patient is noted to appear lethargic. He does not communicate with the doctor, but is able to follow some commands. The eye exam shows the patient is unable to look up or down, but has no problem looking right or left. The patient is drooling, and the parents explain he is often unable to swallow his saliva. The abdominal exam shows an enlarged liver and spleen (shown below). His muscles are generally weak and rigid. The doctor sends the patient for a blood test, which shows abnormal appearing white blood cells (shown below) that testing reveals have extremely high levels of cholesterol.